I have this dataframe that is called xTest and this vector x both of type numpy.ndarray x length is 197 xtest's shape is (25000, 197). I am trying of generate a new column for xTest called prediction by getting the dot product of xTest and x.

I tried:

xTest["pred"] = np.dot(xTest,x)

and

xTest["pred"] = xTest.dot(x)

I keep getting this error: IndexError: only integers, slices (:), ellipsis (...), numpy.newaxis (None) and integer or boolean arrays are valid indices.

xTest is already one hot encoded.

UPDATE : Thanks to the great person who pointed it out below I was able to solve it like this

df = pd.DataFrame()
df["pred"] = np.dot(xTest,x)

CodePudding user response：

Beacuse xTest is a numpy array and not a dataframe, you cannot use strings to index it. You're trying to access pred on xTest assuming xTest is a dataframe, but it's only a single column from a dataframe.